Cardiac Arrest during Temporary Clipping for Ruptured Internal Carotid Artery Aneurysm: A Case Report.

Mechanical stimulation of the trigeminal nerve during craniofacial, skull base, or dental surgeries may cause bradycardia, hypotension, or cardiac arrest. This phenomenon is called trigeminal cardiac reflex (TCR). We encountered a rare case of a patient who experienced sinus arrest due to temporary clipping of the intracranial carotid artery during the clipping of a ruptured aneurysm. We discuss possible reasons for the occurrence of TCR in this case. A man in his 30s with no medical history presented with a sudden-onset headache. Computed tomography revealed a subarachnoid hemorrhage in the basal cistern and left Sylvian fissure. Angiography revealed a saccular aneurysm of the left internal carotid-anterior choroidal artery. A left frontotemporal craniotomy and dural incision were performed, followed by a trans-Sylvian approach. Cardiac arrest occurred twice during the temporary clipping of the intracranial carotid artery. After surgery, we performed a cardiac ultrasound echo and a 1-week Holter electrocardiogram. Neither showed abnormalities. No arrhythmia or cardiac events were observed over a one and half-year follow-up period. The cardiac arrest might have been triggered by the stimulation of the trigeminal nerve in the internal carotid artery. The repeated and anatomical features of this case suggest that TCR triggered cardiac arrest. The high probability that cardiac arrest was induced by trigeminal nerve stimulation should be considered during the temporary clipping of the internal carotid artery. However, the predisposing factors and exact underlying mechanisms for these arrhythmias remain unknown and require further investigation.